From db39e6cb722083787399175e9325f1b6c49f89de Mon Sep 17 00:00:00 2001 From: Aravind Sirsikar Date: Thu, 19 May 2016 21:23:34 +0530 Subject: Add support for Split block handling for EGPRS UL TBF This patch will modify the EGPRS UL TBF flow to support Split block handling. --- src/encoding.cpp | 6 ++- src/tbf.h | 12 +++++ src/tbf_ul.cpp | 162 +++++++++++++++++++++++++++++++++++++++++++++++-------- 3 files changed, 156 insertions(+), 24 deletions(-) diff --git a/src/encoding.cpp b/src/encoding.cpp index 44a0a0d..a078e23 100644 --- a/src/encoding.cpp +++ b/src/encoding.cpp @@ -276,7 +276,8 @@ void Encoding::write_packet_uplink_assignment( bitvec_write_field(dest, wp,0x0,1); // No CONTENTION_RESOLUTION_TLLI bitvec_write_field(dest, wp,0x0,1); // No COMPACT reduced MA bitvec_write_field(dest, wp,tbf->current_cs().to_num()-1, 4); // EGPRS Modulation and Coding IE - bitvec_write_field(dest, wp,0x0,1); // No RESEGMENT + /* No RESEGMENT */ + bitvec_write_field(dest, wp, 0x1, 1); bitvec_write_field(dest, wp,ws_enc,5); // EGPRS Window Size bitvec_write_field(dest, wp,0x0,1); // No Access Technologies Request bitvec_write_field(dest, wp,0x0,1); // No ARAC RETRANSMISSION REQUEST @@ -613,7 +614,8 @@ static void write_packet_uplink_ack_egprs( /* CHANNEL_CODING_COMMAND */ bitvec_write_field(dest, wp, tbf->current_cs().to_num() - 1, 4); - bitvec_write_field(dest, wp, 0, 1); // 0: no RESEGMENT (nyi) + /* 0: no RESEGMENT (nyi) */ + bitvec_write_field(dest, wp, 1, 1); bitvec_write_field(dest, wp, 1, 1); // PRE_EMPTIVE_TRANSMISSION, TODO: This resembles GPRS, change it? bitvec_write_field(dest, wp, 0, 1); // 0: no PRR_RETRANSMISSION_REQUEST, TODO: clarify bitvec_write_field(dest, wp, 0, 1); // 0: no ARAC_RETRANSMISSION_REQUEST, TODO: clarify diff --git a/src/tbf.h b/src/tbf.h index ad8ad4c..54c605f 100644 --- a/src/tbf.h +++ b/src/tbf.h @@ -439,6 +439,18 @@ struct gprs_rlcmac_ul_tbf : public gprs_rlcmac_tbf { int assemble_forward_llc(const gprs_rlc_data *data); int snd_ul_ud(); + egprs_rlc_ul_reseg_bsn_state handle_egprs_ul_spb( + const struct gprs_rlc_data_info *rlc, struct gprs_rlc_data *block, + uint8_t *data, const uint8_t block_idx); + + egprs_rlc_ul_reseg_bsn_state handle_egprs_ul_first_seg( + const struct gprs_rlc_data_info *rlc, struct gprs_rlc_data *block, + uint8_t *data, const uint8_t block_idx); + + egprs_rlc_ul_reseg_bsn_state handle_egprs_ul_second_seg( + const struct gprs_rlc_data_info *rlc, struct gprs_rlc_data *block, + uint8_t *data, const uint8_t block_idx); + /* Please note that all variables here will be reset when changing * from WAIT RELEASE back to FLOW state (re-use of TBF). * All states that need reset must be in this struct, so this is why diff --git a/src/tbf_ul.cpp b/src/tbf_ul.cpp index e01fa83..90c957b 100644 --- a/src/tbf_ul.cpp +++ b/src/tbf_ul.cpp @@ -138,6 +138,134 @@ struct msgb *gprs_rlcmac_ul_tbf::create_ul_ack(uint32_t fn, uint8_t ts) return msg; } +egprs_rlc_ul_reseg_bsn_state gprs_rlcmac_ul_tbf::handle_egprs_ul_second_seg( + const struct gprs_rlc_data_info *rlc, struct gprs_rlc_data *block, + uint8_t *data, const uint8_t block_idx) +{ + const struct gprs_rlc_data_block_info *rdbi = + &rlc->block_info[block_idx]; + + uint8_t *rlc_data = &(block->block[0]); + + if (block->block_status_ul & EGPRS_RESEG_FIRST_SEG_RXD) { + LOGP(DRLCMACUL, LOGL_DEBUG, + "Second seg is received " + "first seg is already present " + "set the status to complete\n"); + block->block_status_ul = EGPRS_RESEG_DEFAULT; + + block->len += Decoding::rlc_copy_to_aligned_buffer(rlc, + block_idx, data, rlc_data + block->len); + block->block_info.data_len += rdbi->data_len; + return EGPRS_RESEG_DEFAULT; + + } else if (block->block_status_ul == EGPRS_RESEG_DEFAULT) { + LOGP(DRLCMACUL, LOGL_DEBUG, + "Second seg is received " + "first seg is not received " + "set the status to second seg received\n"); + block->len = Decoding::rlc_copy_to_aligned_buffer(rlc, + block_idx, data, rlc_data); + block->block_status_ul = EGPRS_RESEG_SECOND_SEG_RXD; + block->block_info = *rdbi; + return EGPRS_RESEG_SECOND_SEG_RXD; + } + return EGPRS_RESEG_INVALID; +} + + +egprs_rlc_ul_reseg_bsn_state gprs_rlcmac_ul_tbf::handle_egprs_ul_first_seg( + const struct gprs_rlc_data_info *rlc, struct gprs_rlc_data *block, + uint8_t *data, const uint8_t block_idx) +{ + const struct gprs_rlc_data_block_info *rdbi = + &rlc->block_info[block_idx]; + uint8_t *rlc_data = &(block->block[0]); + + if (block->block_status_ul & EGPRS_RESEG_SECOND_SEG_RXD) { + LOGP(DRLCMACUL, LOGL_DEBUG, + "First seg is received " + "second seg is already present " + "set the status to complete"); + static uint8_t seg_data[RLC_MAX_LEN]; + uint8_t len = block->len; + + /* Assembling the resegmented split blocks */ + memcpy(seg_data, block->block, len); + block->len = Decoding::rlc_copy_to_aligned_buffer(rlc, + block_idx, data, rlc_data); + memcpy(block->block + block->len, seg_data, len); + block->len += len; + block->block_info.data_len += rdbi->data_len; + block->block_status_ul = EGPRS_RESEG_DEFAULT; + return EGPRS_RESEG_DEFAULT; + } else if (block->block_status_ul == EGPRS_RESEG_DEFAULT) { + LOGP(DRLCMACUL, LOGL_DEBUG, + "First seg is received " + "second seg is not received " + "set the status to first seg " + "received\n"); + + block->block_status_ul = EGPRS_RESEG_FIRST_SEG_RXD; + block->len = Decoding::rlc_copy_to_aligned_buffer(rlc, + block_idx, data, rlc_data); + block->block_info = *rdbi; + return EGPRS_RESEG_FIRST_SEG_RXD; + } + return EGPRS_RESEG_INVALID; +} + +egprs_rlc_ul_reseg_bsn_state gprs_rlcmac_ul_tbf::handle_egprs_ul_spb( + const struct gprs_rlc_data_info *rlc, struct gprs_rlc_data *block, + uint8_t *data, const uint8_t block_idx) +{ + const struct gprs_rlc_data_block_info *rdbi = + &rlc->block_info[block_idx]; + + LOGP(DRLCMACUL, LOGL_NOTICE, + "Got SPB(%d) " + "cs(%s) data block with BSN (%d), " + "TFI(%d).\n", rdbi->spb, rlc->cs.name(), rdbi->bsn, + rlc->tfi); + + egprs_rlc_ul_reseg_bsn_state re_assemble_status = EGPRS_RESEG_INVALID; + + /* Section 10.4.8b of 44.060*/ + if (rdbi->spb == 2) + re_assemble_status = handle_egprs_ul_first_seg(rlc, + block, data, block_idx); + else if (rdbi->spb == 3) + re_assemble_status = handle_egprs_ul_second_seg(rlc, + block, data, block_idx); + else { + LOGP(DRLCMACUL, LOGL_ERROR, + "Not supported SPB for this EGPRS configuration\n"); + OSMO_ASSERT(false); + } + + /* + * When the block is successfully constructed out of segmented blocks + * upgrade the MCS to the type 2 + */ + if (re_assemble_status == EGPRS_RESEG_DEFAULT) { + switch (GprsCodingScheme::Scheme(rlc->cs)) { + case GprsCodingScheme::MCS3 : + block->cs = GprsCodingScheme::MCS6; + break; + case GprsCodingScheme::MCS2 : + block->cs = GprsCodingScheme::MCS5; + break; + case GprsCodingScheme::MCS1 : + block->cs = GprsCodingScheme::MCS4; + break; + default: + OSMO_ASSERT(false); + break; + } + } + return re_assemble_status; +} + int gprs_rlcmac_ul_tbf::rcv_data_block_acknowledged( const struct gprs_rlc_data_info *rlc, uint8_t *data, struct pcu_l1_meas *meas) @@ -219,36 +347,26 @@ int gprs_rlcmac_ul_tbf::rcv_data_block_acknowledged( rdbi->bsn, m_window.v_q(), m_window.mod_sns(m_window.v_q() + ws - 1)); block = m_rlc.block(rdbi->bsn); - block->block_info = *rdbi; - block->cs = rlc->cs; OSMO_ASSERT(rdbi->data_len <= sizeof(block->block)); rlc_data = &(block->block[0]); - /* TODO: Handle SPB != 0 -> Set length to 2*len, add offset if - * 2nd part. Note that resegmentation is currently disabled - * within the UL assignment. - */ + if (rdbi->spb) { - LOGP(DRLCMACUL, LOGL_NOTICE, - "Got SPB != 0 but resegmentation has been " - "disabled, skipping %s data block with BSN %d, " - "TFI=%d.\n", rlc->cs.name(), rdbi->bsn, - rlc->tfi); - continue; + egprs_rlc_ul_reseg_bsn_state re_assemble_status = + handle_egprs_ul_spb(rlc, block, + data, block_idx); + if (re_assemble_status != EGPRS_RESEG_DEFAULT) + return 0; + } else { + block->block_info = *rdbi; + block->cs = rlc->cs; + block->len = + Decoding::rlc_copy_to_aligned_buffer(rlc, + block_idx, data, rlc_data); } - block->len = - Decoding::rlc_copy_to_aligned_buffer(rlc, block_idx, data, - rlc_data); - LOGP(DRLCMACUL, LOGL_DEBUG, "%s: data_length=%d, data=%s\n", name(), block->len, osmo_hexdump(rlc_data, block->len)); - - /* TODO: Handle SPB != 0 -> set state to partly received - * (upper/lower) and continue with the loop, unless the other - * part is already present. - */ - /* Get/Handle TLLI */ if (rdbi->ti) { num_chunks = Decoding::rlc_data_from_ul_data( -- cgit v1.2.3